U.S. patent number 6,439,605 [Application Number 09/725,893] was granted by the patent office on 2002-08-27 for air bag and air bag device.
This patent grant is currently assigned to Takata Corporation. Invention is credited to Katsuhiro Ariyoshi.
United States Patent |
6,439,605 |
Ariyoshi |
August 27, 2002 |
Air bag and air bag device
Abstract
An air bag is formed of a panel portion with a gas introducing
port, a partition wall situated inside the panel portion for
partitioning an inside of the panel portion into a first chamber
located on a front side of an automobile and a second chamber
located on a rear side of the automobile, a gas passage situated
between the first chamber and the second chamber, and at least one
vent hole formed in the panel portion at the second chamber. An air
bag device includes, in addition to the air bag, a retainer for
retaining the air bag, an inflator for expanding the air bag, and a
lid for covering the retainer. In case a collision speed is small
or the passenger is relatively small, the passenger can be received
by the air bag with a soft touch. In case the collision speed is
large or the passenger is large, the passenger can be securely
received by the first and second chambers.
Inventors: |
Ariyoshi; Katsuhiro (Tokyo,
JP) |
Assignee: |
Takata Corporation (Tokyo,
JP)
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Family
ID: |
18401717 |
Appl.
No.: |
09/725,893 |
Filed: |
November 30, 2000 |
Foreign Application Priority Data
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Dec 8, 1999 [JP] |
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11-349131 |
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Current U.S.
Class: |
280/739; 280/740;
280/743.1 |
Current CPC
Class: |
B60R
21/233 (20130101); B60R 21/239 (20130101); B60R
2021/23324 (20130101) |
Current International
Class: |
B60R
21/16 (20060101); B60R 021/30 () |
Field of
Search: |
;280/729,739,740,743.1,743.2,738 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2-132555 |
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Nov 1990 |
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JP |
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3-281460 |
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Dec 1991 |
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JP |
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6-191370 |
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Jul 1994 |
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JP |
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7-329667 |
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Dec 1995 |
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JP |
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9-295545 |
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Nov 1997 |
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JP |
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10-44914 |
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Feb 1998 |
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JP |
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10-71904 |
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Mar 1998 |
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JP |
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Primary Examiner: Dickson; Paul N.
Assistant Examiner: Royal, Jr.; Paul
Attorney, Agent or Firm: Kanesaka & Takeuchi
Claims
What is claimed is:
1. An air bag comprising: an air bag panel portion with a gas
introducing port, a partition wall situated inside the panel
portion for partitioning an inside of the panel portion into a
first chamber located on a front side of an automobile and having
the gas introducing port, and a second chamber located on a rear
side of the automobile, a gas passage situated between the first
chamber and the second chamber, at least one vent hole formed in
the panel portion at the second chamber, and a reverse-flow
preventing device formed in the gas passage between the panel
portion and the partition wall and situated between the first and
second chambers for allowing a gas to flow from the first chamber
to the second chamber and preventing the gas from flowing from the
second chamber to the first chamber, said reverse-flow preventing
device being a valve made of a sheet, said at least one vent hole
passing through the panel portion and the sheet of the valve, which
are sewed together around a circumferential portion of the vent
hole.
2. An air bag according to claim 1, wherein said partition wall is
a flexible sheet having a main portion for separating the first and
second chambers, and a plurality of flaps extending from the main
portion, at least one of the flaps extending toward the second
chamber to form the reverse-flow preventing device between the flap
and a part of the panel portion situated adjacent thereto.
3. An air bag according to claim 2, wherein said flexible sheet has
upper, lower and two side flap portions, said upper flap portion
being fixed to the panel portion, and two side flap portions being
at least partly fixed to the panel portion.
4. An air bag according to claim 1, wherein said gas passage is
provided on only a lower surface side of the panel portion, or on
only the lower surface side and two lateral sides of the panel
portion.
5. An air bag according to claim 1, wherein said second chamber has
a capacity greater than that of the first chamber.
6. An air bag device comprising the air bag according to claim 1
and an inflator for supplying a gas into the air bag to expand the
same.
7. An air bag comprising: an air bag panel portion with a gas
introducing port, a partition wall situated inside the panel
portion for partitioning an inside of the panel portion into a
first chamber located on a front side of an automobile and having
the gas introducing port, and a second chamber located on a rear
side of the automobile, said partition wall being a flexible sheet
having a main portion for separating the first and second chambers
and upper, lower and two side flap portions extending from the main
portion, said upper flap portion being fixed to the panel portion,
and said two side flap portions being at least partly fixed to the
panel portion, a gas passage situated between the first chamber and
the second chamber, at least one vent hole formed in the panel
portion at the second chamber, and a reverse-flow preventing device
formed in the gas passage between the panel portion and the
partition wall and situated between the first and second chambers
for allowing a gas to flow from the first chamber to the second
chamber and preventing the gas from flowing from the second chamber
to the first chamber, at least one of the flap portions extending
toward the second chamber to form the reverse-flow preventing
device between the flap portion and a part of the panel portion
situated adjacent thereto.
8. An air bag according to claim 7, wherein said at least one vent
hole is formed in the side flap portion and the panel portion to
penetrate therethrough, said side flap portion and the panel
portion being fixed together around the at least one vent hole.
9. An air bag according to claim 8, wherein said lower flap portion
is disposed over the panel portion without being fixed thereto.
10. An air bag comprising: an air bag panel portion with a gas
introducing port, a partition wall situated inside the panel
portion for partitioning an inside of the panel portion into a
first chamber located on a front side of an automobile and having
the gas introducing port, and a second chamber located on a rear
side of the automobile, said partition wall being a flexible sheet
having a main portion for separating the first and second chambers
and a plurality of flaps extending from the main portion and
located adjacent the panel portion, at least one of the flaps
extending toward the second chamber adjacent the panel portion, a
gas passage situated between the first chamber and the second
chamber, at least one vent hole formed in the panel portion at the
second chamber, and a reverse-flow preventing device formed in the
gas passage between the panel portion and the partition wall and
situated between the first and second chambers for allowing a gas
to flow from the first chamber to the second chamber and preventing
the gas from flowing from the second chamber to the first chamber,
said at least one of the flaps extending toward the second chamber
forming the reverse-flow preventing device between said at least
one of the flaps and a part of the panel portion situated adjacent
thereto so that in a condition that the air bag is fully opened,
when the second chamber is pushed, the gas in the second chamber is
ejected through the at least one vent hole, and when the partition
wall is pushed through the second chamber toward the first chamber
at a pressure greater than that in the first chamber, the gas in
the first chamber is ejected outside the air bag through the
reverse-flow preventing device and the at least one vent hole to
thereby absorb impact at plural stages.
11. An air bag according to claim 10, wherein said plurality of
flaps forms the reverse-flow preventing device between each of the
flaps and the panel portion.
Description
BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT
The invention relates to an air bag for protecting a passenger in a
vehicle, such as an automobile, at an emergency time, i.e. a
collision, and an air bag device including the air bag. More
particularly, it relates to an air bag having a plurality of
chambers therein, and an air bag device thereof.
An air bag device, as well known, is a device for expanding an air
bag for receiving a passenger therewith at a collision time of an
automobile or the like. The air bag is provided with a vent hole,
and when the passenger hits the expanded air bag very hard, a gas
in the air bag gradually flows out through the vent hole to absorb
an impact.
In case an automobile speed and a physical structure of a passenger
are different, a kinetic energy to a forward direction of the
passenger is also varied. Thus, an air bag device satisfying the
following items (1) and (2) is ideal.
(1) In case the kinetic energy to the forward direction of the
passenger is large, it is preferable that a bag resistance is made
large, and energy absorbing stroke and time are made long; and
(2) In case the kinetic energy to the forward direction of the
passenger is relatively small, it is necessary to expand a bag to
provide a small resistance against the passenger.
Japanese Utility Model Publication (KOKAI) No. 2-132555 discloses
an air bag device, wherein an air bag is partitioned into two
chambers separated in the vertical direction, a gas is introduced
into an upper chamber through a lower chamber, and vent holes are
provided to the upper side chamber. In the air bag device, at a
time of collision of an automobile, first, a chest portion of the
passenger is received by a first chamber having a high inner
pressure, and then, a head portion of the passenger is received by
a second chamber having a weak inner pressure. The air bag can not
attain the above items (1) and (2).
It is an object of the invention to provide an air bag device,
wherein when a passenger hits an air bag at a relatively low speed,
the passenger is received by the air bag with a relatively soft
touch, and in case the passenger hits the air bag at a relatively
high speed, the passenger is securely received by the air bag at
two stages.
Further objects and advantages of the invention will be apparent
from the following description of the invention.
SUMMARY OF THE INVENTION
In the present invention, an air bag includes a gas introducing
port, a partition wall for partitioning the air bag into a first
chamber having the gas introducing port and disposed on a forward
side of an automobile and a second chamber disposed on a rear side
thereof, a gas passage for communicating between the first chamber
and the second chamber, and a vent hole disposed at the second
chamber. An air bag device includes, in addition to the air bag, a
gas generator for supplying gas to the air bag.
In the air bag as described above, when the gas generator is
operated at a time of collision of the automobile or the like,
first, the first chamber expands, and then the second chamber is
expanded by the gas passing through the gas passage. In case the
passenger hits the expanded air bag, the gas gradually flows out
through the vent hole from the second chamber, so that an impact
energy is absorbed and the passenger is received by the second
chamber with a relatively soft touch. Thus, when the passenger hits
the air bag with a small speed, the passenger can be sufficiently
received with only a gas flow-out from the second chamber.
In case the passenger hits the air bag with a high speed, a body of
the passenger also presses the first chamber from the second
chamber side through the partition wall. The gas in the first
chamber flows into the second chamber through the gas passage and
flows out through the vent hole. Since a gas flow-out resistance at
this time is large, the passenger can be securely received by the
first chamber. Of course, since the gas in the first chamber is
drawn into the second chamber, the impact energy of the passenger
is absorbed.
As described above, since the air bag is partitioned into the first
and second chambers, the passenger can be received with different
impact absorbing characteristics at two stages. Incidentally, the
air bag may be partitioned into first, second and third chambers or
more than that.
In the present invention, it is preferable to provide a gas
reverse-flow preventing device for preventing the gas from
reversely flowing from the second chamber to the first chamber.
With the gas reverse-flow preventing device, in case the second
chamber is pressed by the passenger, a gas-reverse flow from the
second chamber to the first chamber can be prevented, and a gas
flow quantity for flowing out from the second chamber through the
vent hole can be rationalized to thereby properly absorb the impact
energy of the passenger.
The gas reverse-flow preventing device is a valve formed of a
sheet. The vent hole penetrates through the sheet constituting the
valve. A circumference of the vent hole provided on the sheet may
be united to the air bag. Thus, when the-gas in the first chamber
flows out from the vent hole through the second chamber, a flow
resistance becomes large and the passenger can be sufficiently
received by the first chamber.
In the present invention, it is preferable that the gas passage is
disposed only on an under surface side of the air bag, or on both
sides and the under surface side of the air bag. Thus, when the gas
flows into the second chamber from the first chamber, the gas
mainly enters a lower side of the second chamber to thereby start
expanding the second chamber from the lower side. As a result, a
passenger facing surface of the air bag expands to approach the
passenger from the lower side thereof.
In the present invention, it is preferable that the capacity of the
second chamber is larger than that of the first chamber, so that
most part of the impact is absorbed by the second chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an air bag according to the present
invention;
FIG. 2 is a seeing-through inner perspective view of the air bag of
the invention;
FIG. 3 is a sectional view taken along line 3--3 in FIG. 1;
FIG. 4 is a sectional view taken along line 4--4 in FIG. 3;
FIG. 5 is a sectional view taken along line 5--5 in FIG. 3;
FIG. 6 is a sectional view taken along line 6--6 in FIG. 3; and
FIG. 7 to FIG. 12 are explanatory views for explaining an air bag
expanding operation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereunder, with reference to the accompanying drawings, an
embodiment of an air bag according to the present invention is
explained. FIG. 1 is a perspective view of an embodiment of an air
bag for a front passenger seat according to the invention; FIG. 2
is a seeing-through inner perspective view of the air bag for the
front passenger seat according to the invention; FIG. 3 is a
sectional view taken along line 3--3 in FIG. 1; FIG. 4 to FIG. 6
are sectional views taken along lines 4--4 to 6--6 in FIG. 3; and
FIG. 7 to FIG. 12 are explanatory views of air bag expanding
operations.
The air bag device includes a retainer 1 having a container shape,
a front surface of which is open; an air bag 2 housed in the
retainer 1; an inflator, i.e. gas generator, 3 for expanding the
air bag 2; and a lid, not shown, for covering the front surface of
the retainer 1. An edge portion of a gas introducing port 4 of the
air bag 2 is attached to the retainer 1.
The air bag 2 has an outer or panel portion structured by a pair of
side panels 5, and a front panel 6 formed of an upper surface, a
passenger facing surface and a lower surface of the air bag 2 and
surrounding outer circumferences of the side panels 5. The air bag
2 has a gas introduction port 4 at an end portion thereof.
The air bag 2 is divided into a first chamber 11 on a side of gas
introducing port 4 and a second chamber 12 on a side facing a
passenger by a partition wall 10 formed of a cloth or sheet
extending in a vertical direction.
An entire upper side or flap of the partition wall 10 is sewed
together with an upper surface of the air bag 2. Between the air
bag 2 and both sides of the partition wall 10 and between the air
bag 2 and a lower side of the partition wall 10, there are provided
gas passages 13, 14, 15 communicating the first chamber 11 with the
second chamber 12.
To prevent the reverse flow of the gas having passed through the
gas passages 13, 14, 15, there are provided check valves 16, 17, 18
made of cloths or flaps. Base end sides of the respective check
valves 16, 17, 18 are connected to the partition wall 10, and free
end sides thereof extend into the second chamber 12.
The check valves 16, 17 on the both sides of the partition wall 10
face both side panels 5, respectively, and vent holes 19 are
provided to pass through the check valves 16, 17 and the both side
panels 5, respectively. The check valves 16, 17 are sewed together
with the side panels 5 at circumferential portions of the
respective vent holes 19 in a circular shape.
Incidentally, the partition wall 10 is disposed at a portion
relatively close to the gas introducing port 4 so that even if the
passenger hits the air bag very hard, the passenger does not
substantially contact the partition wall 10. A capacity of the
second chamber is larger than that of the first chamber.
Operations of the air bag device with the air bag thus structured
are explained with reference to FIGS. 7 to 12. Incidentally, in
order to make the drawings easily understandable, in FIGS. 7-12,
the vent holes 19 are disposed away from the check valves 16,
17.
When a collision of an automobile is detected, the inflator 3
starts to eject a gas. The gas, as shown in FIG. 7, first expands
the first chamber 11, and then expands the second chamber 12
through the gas passages 13, 14, 15 as shown in FIG. 8. At this
time, the check valves 16, 17, 18 allow the gas to flow into the
second chamber 12 through the gas passages 13, 14, 15.
When a pressure in the second chamber 12 becomes a positive or
appropriate pressure, as shown in FIG. 9, the check valves 16-18
are closed by the pressure.
As shown in FIG. 10, in case the passenger hits the expanded air
bag 2, first, the gas in the second chamber 12 flows out through
the vent holes 19, and an impact energy is absorbed. Although the
pressure in the second chamber 12 is raised because of the
passenger hitting the air bag, the check valves 16 to 18 remain
closed, so that the reverse flow of the gas from the second chamber
12 to the first chamber 11 is prevented. The gas in the second
chamber 12 flows outside the air bag 2 solely through the vent
holes 19 to thereby absorb the impact energy of the passenger.
In case a collision speed of the automobile is small or the
passenger is relatively small, the passenger is stopped at a state
shown in FIG. 10 or right before a state shown in FIG. 11. During
this period, since the gas in the second chamber 12 relatively
easily flows out through the vent holes 19, the passenger is
received by the second chamber 12 with a relatively soft touch.
In case the collision speed of the automobile is relatively large
or the passenger is large, the passenger is further moved forward
from the state shown in FIG. 10, and abuts against the partition
wall 10, as shown in FIG. 11, to press the first chamber 11, too.
Thus, an inner pressure in the first chamber 11 becomes higher than
an inner pressure in the second chamber 12 to thereby open the
check valves 16, 17, 18, so that the gas in the first chamber 11
flows out from the vent holes 19 through the second chamber 12.
Thus, the impact energy of the passenger is further absorbed.
Incidentally, since the gas in the first chamber 11 passes through
the narrow gas passages 13, 14, 15, and further enters the check
valves 16, 17, 18 to reach the vent holes 19, an exhausting speed
of the gas in the first chamber 11 is smaller than that of the gas
in the second chamber 12 as shown in FIG. 10. Therefore, the speed
for crushing the first chamber 11 is small to thereby positively
receive the passenger thereat.
As described hereinabove, according to the air bag, the impact
energy of the passenger can be sufficiently absorbed. Also, in case
the collision speed is small or the passenger is relatively small,
the passenger can be softly received by the air bag. Also, in case
the collision speed is large or the passenger is large, the
passenger can be securely received by the air bag.
In the present embodiment, the gas passages 13, 14, 15 are disposed
on both sides and the lower surface side of the air bag 2, the
lower side of the second chamber 12 starts expanding first, and a
forward edge surface, i.e. passenger facing surface, of the air bag
2 expands in an inclined state. Incidentally, the gas passage may
be provided only at the lower surface of the air bag 2.
In the present embodiment, since the vent holes 19 are provided to
the check valves 16, 17, the exhausting speed of the gas from the
first chamber 11 can be sufficiently made small. Also, since the
check valves 16, 17 are sewed together with the side panels 5
around the vent holes 19, the check valves 16, 17 are positively
positioned on the sides of the second chamber 12.
The air bag and the air bag device of the above embodiment are for
the front passenger seat. However, the present invention can be
also applied to a driver's seat air bag and rear seat air bags.
As described above, according to the present invention, the
passenger can be received at plural stages with different impact
absorbing characteristics. The impact energy of the passenger can
be sufficiently absorbed. Also, in case the collision speed is
small or the passenger is relatively small, the passenger can be
softly received by the air bag. Further, in case the collision
speed is large or the passenger is large, the passenger can be
securely received at two stages.
While the invention has been explained with reference to the
specific embodiments of the invention, the explanation is
illustrative and the invention is limited only by the appended
claims.
* * * * *